The present invention relates generally to adjustable mounting mechanisms and more specifically to a variation of an adjustable mounting mechanism known as a kinematic mount.
A kinematic mount is a known mechanism for coupling two elements so that their relative orientation may be adjusted. In a typical configuration, the first element has three engagement elements that engage the second element at three engagement portions, the first and second elements are biased toward each other, and at least two of the engagement elements are protrusions that are adjustable to provide the desired orientation. The other engagement element, whether or not adjustable, is also typically formed as a protrusion.
The adjustable protrusions are typically implemented as adjustment screws, carried by the first element and having rounded, possibly hemispherical, ends that engage the second element. The second element is formed with portions that engage the protrusions, typically a portion surrounding a hemispherical hole or a conical hole, a portion surrounding a semi-cylindrical groove or a V-groove, and a flat portion. The bottom of the groove is typically in line with the center of the hole, and the flat portion is to one side of the groove.
The three points at which the first element engages the second element may be thought of as defining a reference plane, with the normal to the reference plane defining a reference direction. A setting where the adjustment screws extend perpendicular to the reference plane can be considered a nominal zero-tilt setting. If the first element is considered to be characterized by an axis that extends parallel to the direction of the screws, the mount allows the first element to be tilted so that its axis has desired components along two non-parallel directions perpendicular to the reference direction.
One known use of a kinematic mount is in optical instruments where the tilt angles of mirrors have to be adjusted. In a typical instrument, the mirror is vertical and must be mounted to a horizontal optical bench. Tilt adjustments may be provided by mounting a right-angled bracket having an approximately vertical plate portion, mounting the mirror to a supporting plate, and configuring the vertical plate portion and the mirror-supporting plate as a kinematic mount. The adjustment screws would extend horizontally (generally perpendicular to the mirror surface). Depending on whether the adjustment screws are carried by the vertical plate portion or the mirror-supporting plate, the adjustment would be made from behind the mirror or from in front of the mirror. Since clearances tend to be rather limited, adjustments tend to be difficult.